#include <iostream>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
int main()
{
    //stdout -> 1
    printf("hello printf 1\n");
    fprintf(stdout,"hello fprintf 1\n");

    // stderr -> 2
    perror("hello perror 2"); //stderr

    const char *s1 = "hello write 1\n";
    write(1, s1, strlen(s1));

    const char *s2 = "hello write 2\n";
    write(2, s2, strlen(s2));

    // cout -> 1
    std::cout << "hello cout 1" << std::endl;
    // cerr -> 2
    std::cerr << "hello cerr 2" << std::endl;

   return 0;
}
